Tank



May 4, I954 T. T. WOODSON TANK Fig.2.

LINN f1:

Inventor- Thornas T. Woodson,

His Attorney- Patented May 4, 1954 Thomas Woodson Bridgeport, Connassignor toGeneraLElectric Company, a. corporation or New 'YorkApplicationJanuary 14, 1950, Serial No. 138,663-

.1 Glaim. 1.

This invention relates to tan improved-tank. and the methodsofconstructing the samayand in particular relates toanimprovedendaclosure. con.- struction in tanks: having-.an end. wall. orrwallsattached; to .a :body wall in telescoping. relation therewith.

Among the objects of myxinvention are to pro-.- vide :a method of.construction which willzsubstantially reducermaterial wastage in the'fa'bri cation oftanksandthezlike; which willprovide a .fluidetight.jiointbetween the closure member and body wall withoutthe necessity ofaccurate: 1y dimensioning the rim. of .the closure member with respect.to the Lbody. wall; which lends itself to mass production "withrelatively simple tools and .by unskilledlahor; which will functioneffectively in the "manufacture of irregularly shaped tanks; whichzwillpro'ducea tank or tub structure in which the: relative thickness ofthe body wall and end walls may bees desired; and

of many types of low-pressure tanks or vessels.

Certain of the advantagesderivi-ngirom the .use of the invention-Tierexample those relating to material costsaving, and mass production withsimple tools-are particularly. "important. in the manufacture ofwashing. machine tubs inathe highly competitive and cost-consciouswashing machine industry. The present-methods ofmanufacturing washingmachine. tubs comprise variants of the basic technique of deep-drawingthe tub and suspending it within an apron or mounting it onaiwrap-"around skirt. In the first of these, the apron provides externalsupport for the tub and a decorative "housing therefor; in the second,the tub may "be exposed to view *and the skirt simulates an'extensionxofthe tub while providing a supporting base. The waste in the drawingblank'amounts ordinarily to about'38- and for various reasons therejects due tofimperfections in the drawn tub are high. Also, it isentirely impracticable to attempt to produce a .drawn tub havingcontrolled 'oroptional differences in thickness of'the sidewall'relative to the bottom.

Briefly stated, a preferred method of practicing my invention comprisesforming the body; wall of the tub or tank by wrapping or rolling arectangular blank into a cylindrical or prismatic form-in which latterterm I mean to include polygonal shapes whose sides are not normal tothe end surfaces-and joining the respective ends by-a; simplestructure-such 9:578 :mash, seam, weld. I then provide a closure memberhaving a rigid side rim configuration, which ;1; rovides a 'dDVBF tailedspace or pocketof which the :body wall is an element. I prefer to spotweld the closure member to the body wall andwaccordingly the extremeouter dimension of the rim places; the closure rim sufficiently-closelya ainst-the Ibody wall for welding thereto at relatively closeintervals. A, feature of particular importance in the manufacture ofpolygonalytubs is that-the closure rim may-be spaced from the body wallat the corner locations, thus.eli-minating, the necessity of maintainingclose dimensional. tolerances at suchlocations. Whatever the tub-shape,the joint between the endzand-wall structures is made liquid tightbyinserting within the dovetail space a distortable filler or-gasket-ofrubber or -othersuitable material. Said gasketis :of ring form so as-topresent nooverlapping or bufitipints along which leakage might occur.The insertion of said gasket may be accommished-after the fabricated andmutually secured body/and-closure members have been; given theirprotective or decorative finish. The body wall may provide th tubsupprtin -structure. th re y. li ting th need for separatesupportingmeans.:I-f structural; considerationsso require, the body wall, may be=ofheavier :gauge than the closure member, rrviccv r a- In the accompanyingdrawing, :Fig. .Lds a side elevation, in section, showing ioneiorm -01.tanl constructed pursuant-1m the present invention; Fig. .2,= is'aufragmentary side elevation similar to Fig. 1 with fillerstrip-removed; :Fig. .-3':isa view similar to Fig. 2 but showingthe;-1'iller-.-strip in inserted position, saidzfigure beingtaken-.onrlines B -:3 iOf' Rig-' 3 'Eig. 45shows aplanview-ofsalportiongof'the completed 'ta-nk, the "side wall being insection zimmediatelygabove the :filler strip; 5 i-issimilar to Fig. .3,but showing ;.a slightly (infer- .entffillerconfiguration; :andgliig,v6: is a side-sec: tional elevation :of the .filler strip of Fig. 5:showing" its .relaxed shape.

In Eig. lithe tub -.l comprises :atubular bodylz, a. closure 3'esecure'd internally thereof,- and re. filler strip LOI': gasket :'4.:sealing :the, joint ibetween thelbodyswall and :closure. In the opentopped tub shown, the closure Tforms :theibottom thereof, but it will beunderstood that .a similarplosure may be applied at each end of the bodywall, to form a closed-ended tank. As shown, the disposition of theclosure 4 intermediate the ends of the body wall adapts the lower end ofsaid wall as a supporting base to which legs or the like may be aflixedif desired. The body structure may be cylindrical or prismatic, asdesired. When prismatic, as is frequently the practice in washingmachine tubs, it is advantageous that corners between adjacent planesurfaces be somewhat rounded rather than sharply angular. The bodystructure may be seamless, or formed by wrapping or rolling arectangular sheet on conventional metal working machinery. The wallmaterial will be appropriate to the contemplated usage of the tub. Myinvention may, in fact, be used with wooden or other non-metallicstructures. When of metal, the ends of the body sheet may be joined inany conventional manner; for example, by a mash seam weld (not shown).Where the tub is to be open topped, the upper edge may be rolled over orbeaded as indicated.

The tub closure or bottom 3 also may be fabricated of any suitablematerial so long as said material will provide a rigid side wall orflange of necessary contour. The closure may be a casting or a molding;or, as will be most common, of drawn or stamped sheet metal, providing arelatively wide side wall or rim. By rolling or other conventionalmeans, the rim is shaped to provide a bottom portion which fitssufficiently snugly against the wall 2 at a multiplicity of pointstherearound to permit structural securement thereto, and an upperportion 6 inwardly ofiset from the rim 5 in angular relation therewith.Said upper portion cooperates with the body wall 2 and the web 1 to forma pocket in which the transverse dimension increases from the mouth ofthe pocket toward the bottom thereof. Figs. 3 and 4 show how the lowerrim portion 5 and a portion of the web 1 may be cut away to provide thenarrow gap 8, which thereby eliminates the necessity of a closelymatching fit between the rim portion and the body wall. Such anarrangement is possible in my invention because the liquid-tight jointbetween the body wall and the closure is provided by the filler strip 4and is not dependent on the means for physically attaching the closuremember to the body wall.

Thesecurement of the closure to the body wall may be by any meansappropriate to the tub material or contemplated usage. In spot welding,it is desirable to apply a large area anvil against the outer wall andstrike the welding electrode against the closure wall. The resultingweld joint is hardly discernible on the body wall. After the tub membershave been assembled and secured, the desired exterior and/or interiorfinish may be applied.

The respective filler strips 44a are of a. resilient material imperviousto the material to be contained in the tub. The strip may be of extrudedor molded material and is closed-ended. When relaxed, the filler stripshould contact the inner wall of the tub throughout the peripherythereof. Its maximum transverse dimension, in section, should be greaterthan the maximum transverse dimension of the pocket, and its verticaldimension such that when the filler strip is placed within the pocket itwill rest upon the base of the pocket and the distortion of the strip bythe walls thereof will effect a substantial area of tight contact withthe respective side walls of the pocket. It is most desirable that theweb I provide a continuous base at the corner areas of the tub wall. Bysoaping or otherwise lubricating the walls of the pocket, the fillerstrip may be manually inserted and driven home within the pocket. Thecircular cross sectional shape of the filler strip shown in Fig. 2 willassume substantially the shape of Fig. 3 after the strip has been forcedinto the pocket. Where it is desired to produce a fillet at the edge ofthe bottom member to avoid dirt-collecting pockets, a filler strip suchas 4a, Fig. 6 will, when inserted produce the relatively smooth uppersurface shown in Fig. 5. Filler strips may be removed and replacedwithout special tools, thus facilitating the maintenance orreconditioning of the tank or tub.

While I have shown a particular embodiment of my invention, it will beunderstood, of course, that I do not wish to be limited thereto sincemany modifications may be made; and I therefore contemplate by theappended claim to cover any such modifications as fall within the truespirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

A receptacle for containing liquid having a shell of polygonal crosssection; an end closure for said shell comprising a central portion ofsubstantially the same polygonal shape as said shell but of smallerdimensions, side walls depending from said central portion at an angleapproaching but not equal to a right angle, a rim extending from saidside walls and closely approaching the inside walls of said shell alongthe rectilinear portions thereof while being spaced from said walls atcorners, and fianges depending from said rim rectilinear portions; meansfor securing said end closure within said shell, portions of the wallsof said shell along with said end closure side walls and rim defining apocket around the periphery of said end closure, said pocket having amaximum width at said rim and decreasing in width toward the mouth ofthe pocket because of the angular relation of said end closure sidewalls, and a continuous resilient and deformable band of a size andshape to fill completely said pocket and being insertable therein andremovable therefrom without modification of the assembled position ofsaid shell and end closure.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 699,174 Hoppes May 6, 1902 1,605,229 Hartmann Nov. 2, 19261,798,071 Deane Mar 24, 1931 2,037,151 Safiord Apr. 14, 1936 2,100,480Hirshman Nov. 30, 1937 2,141,255 Schweller Dec. 27, 1938 2,148,858Freeman et al Feb. 28, 1939 2,234,639 Wallace Mar. 11, 1941 2,344,986Hothersall Mar. 28, 1944 2,346,566 Ford 1 Apr. 11, 1944 2,427,823Turney, Jr Sept. 23, 1947 2,574,273 McLeod Nov. 6, 1951 FOREIGN PATENTSNumber Country Date 769,271 France June 5, 1934

